Hydrokinetic coupling apparatus, in particular for motor vehicle, comprising a needle thrust bearing between the piston and the turbine hub

Abstract

The invention concerns a hydrokinetic apparatus, in particular for motor vehicle, comprising a casing ( 10 ); a turbine wheel ( 16 ) secured in rotation to a hub ( 30 ); a lock-clutch comprising a piston ( 50 ) whereof the radially inner part ( 54 ) is mounted sliding along an outer cylindrical shaft ( 58 ) belonging to the central ring called piston ( 50, 54 ) whereof a rear end surface ( 64 ) extends opposite a transverse surface belonging to the turbine wheel ( 16 )/hub ( 30, 86 ) assembly, and comprising stop means ( 84 ) axially interposed between the central ring and the turbine wheel/hub assembly. The invention is characterised in that are provided radial centering means for axial stop ( 84 ) relative to the hub ( 30, 5 ) or relative to the piston ( 50, 54 ) or relative to the web ( 104 ).

What is claimed is:  
     
       1. A hydrokinetic coupling apparatus, for a motor vehicle, comprising: 
       a casing ( 10 ) having a generally transversely oriented wall ( 36 ) adapted to be coupled in rotation to a driving shaft;  
       a turbine wheel ( 16 ) including an internal plate element ( 104 ) and coupled in rotation to a hub ( 30 ) which is adapted to be counted in rotation to a driven shaft;  
       a lock-up clutch ( 14 ) interposed between the turbine wheel ( 16 ) and the transverse wall ( 36 ), and including, arranged axially between the turbine wheel ( 16 ) and the transverse wall ( 36 ), a generally transversely oriented piston ( 50 ), a radially inner portion ( 54 ) of which is mounted for sliding movement along a cylindrical outer surface ( 58 ) of a central sleeve which an annular transverse rear end face ( 64 ) thereof lies facing a front transverse face of an assembly including the turbine wheel ( 16 ) and hub ( 30 ,  86 ); and  
       a thrust bearing ( 84 ) interposed axially between the annular transverse rear end face ( 64 ) of the central sleeve and the front transverse face ( 102 ) to limit friction there between, a portion ( 88 ) of the thrust bearing extends radially outward beyond said rear end face ( 64 ) and being disposed facing a rear transverse face ( 51 ) of the radially inner portion ( 54 ) of the piston ( 50 ) so as to constitute an axial abutment defining the maximum rearward position of the piston ( 50 ) when the clutch is disengaged;  
       wherein said portion  88  is formed as a ring extension ( 88 ) of a front ring portion  108  of said thrust bearing, said thrust bearing being disposed radially inward of said radially inner portion ( 54 ) of the piston ( 50 ) while ring extension portion  88  extends radially outward beyond said radially inner portion ( 54 ) of the piston ( 50 ) thereby providing said axial abutment to engaging piston  50 ; and  
       wherein said extension ( 88 ) is formed as an elastic member provided to absorb shock when engaging piston  50 .  
     
     
       2. Apparatus according to  claim 1 , wherein the abutment includes an axial bearing ( 84 ) with rolling elements, which is interposed axially between the annular transverse rear end face ( 64 ) of the central sleeve ( 52 ) and the said transverse front face ( 102 ) of the assembly consisting of the turbine wheel and hub, and at least one ring ( 108 ) of the axial thrust bearing ( 84 ) includes a radially oriented annular portion ( 88 ) which lies facing the said transverse rear face ( 51 ) of the radially inner portion ( 54 ) of the piston. 
     
     
       3. Apparatus according to  claim 2 , wherein the at least one ring ( 108 ) is at least one front ring ( 108 ) interposed axially between the central sleeve ( 52 ) and the rolling elements ( 106 ), and extending in a generally radial direction and in facing relationship with the said annular transverse rear end face ( 64 ) of the central sleeve ( 52 ), the said front ring having an annular extension ( 88 ) extending radially outwards beyond the ring ( 108 ) and having the transverse front face ( 89 ) in facing relationship with the said transverse rear face ( 51 ) of the radially inner portion ( 54 ) of the piston ( 50 ). 
     
     
       4. Apparatus according to  claim 1 , wherein the hub ( 30 ) includes a radially oriented plate portion ( 86 ) extending outwards, and in that the axial thrust bearing ( 84 ) is disposed facing the transverse front face ( 102 ) of the said plate portion ( 86 ). 
     
     
       5. Apparatus according to  claim 4 , wherein the turbine wheel ( 16 ) includes a generally radially oriented inner plate element ( 104 ), which is fixed to the plate portion ( 86 ) of the hub ( 30 ). 
     
     
       6. Apparatus according to  claim 5  wherein the said plate element ( 104 ) of the turbine wheel ( 16 ) is adjacent to the transverse front face ( 102 ) of the plate portion ( 86 ) of the hub ( 30 ). 
     
     
       7. Apparatus according to  claim 6 , wherein the said plate element ( 104 ) of the turbine wheel ( 16 ) is interposed axially between the plate portion ( 86 ) of the hub ( 30 ) and the axial thrust bearing ( 84 ). 
     
     
       8. Apparatus according to  claim 2 , wherein the axial thrust bearing ( 84 ) includes a rear ring ( 110 ) interposed axially between the assembly having the turbine wheel ( 16 ) and hub ( 30 ,  86 ) and the rolling elements. 
     
     
       9. Apparatus according to  claim 8  wherein the rear ring ( 110 ) of the axial thrust bearing ( 84 ) is centered axially with respect to one of the plate portion ( 86 ) of the hub ( 30 ), and with respect to the plate element ( 104 ) of the turbine wheel ( 16 ). 
     
     
       10. Apparatus according to  claim 9 , wherein the rear ring ( 110 ) of the axial thrust bearing ( 84 ) is centered radially with respect to the inner periphery ( 112 ) of the plate element ( 104 ). 
     
     
       11. Apparatus according to  claim 10 , wherein the rear ring ( 110 ) of the axial thrust bearing ( 84 ) is centered radially with respect to the plate portion ( 86 ) of the hub ( 30 ). 
     
     
       12. Apparatus according to  claim 3 , wherein the front ring ( 108 ) of the axial thrust bearing ( 84 ) is centered radially with respect to the radially inner portion ( 54 ) of the piston ( 50 ). 
     
     
       13. Apparatus according to  claim 1 , wherein one ring ( 110 ,  108 ) of the thrust bearing is coupled in rotation to one of the turbine wheel ( 16 ,  104 ), the central sleeve, and the piston ( 50 ). 
     
     
       14. Apparatus according to  claim 1 , wherein the thrust bearing ( 84 ) is attached axially to one of the turbine wheel ( 16 ,  104 ,  30 ), the central sleeve ( 52 ), and the piston. 
     
     
       15. The hydrokinetic coupling apparatus according to  claim 1 , wherein said thrust bearing  84  is disposed adjacent to and radially within an inner peripheral edge  112  of said plate  104 . 
     
     
       16. A hydrokinetic coupling apparatus, for a motor vehicle, comprising: 
       a casing ( 10 ) having a generally transversely oriented wall ( 36 ) adapted to be coupled in rotation to a driving shaft;  
       a turbine wheel ( 16 ) including an internal plate element ( 104 ) and coupled in rotation to a hub ( 30 ) which is adapted to be coupled in rotation to a driven shaft;  
       a lock-up clutch ( 14 ) interposed between the turbine wheel ( 16 ) and the transverse wall ( 36 ), and including, arranged axially between the turbine wheel ( 16 ) and the transverse wall ( 36 ), a generally transversely oriented piston ( 50 ), a radially inner portion ( 54 ) of which is mounted for sliding movement along a cylindrical outer surface ( 58 ) of a central sleeve which an annular transverse rear end face ( 64 ) thereof lies facing a front transverse face of an assembly including the turbine wheel ( 16 ) and hub ( 30 ,  86 ); and  
       a thrust bearing ( 84 ) interposed axially between the annular transverse rear end face  64  of the central sleeve and the front transverse face ( 102 ) to limit friction there between, a portion ( 88 ) of the thrust bearing extends radially outward beyond said rear end face ( 64 ) and being disposed facing a rear transverse face ( 51 ) of the radially inner portion ( 54 ) of the piston ( 50 ) so as to constitute an axial abutment defining the maximum rearward position of the piston ( 50 ) when the clutch is disengaged;  
       wherein said thrust bearing  84  is disposed adjacent to and radially within an inner peripheral edge  112  of said plate  104 ; and  
       wherein said thrust bearing  84  is directly coupled to said inner edge  122  and provided with complementary engaging teeth formed in the radially inner edge  112  of the plate and a radially outer portion of a rear ring  110 .  
     
     
       17. The hydrokinetic coupling apparatus according to  claim 16 , wherein said portion  88  is formed as a ring extension ( 88 ) of a front ring portion  108  of said thrust bearing, said thrust bearing being disposed radially inward of said radially inner portion ( 54 ) of the piston ( 50 ) while ring extension portion  88  extends radially outward beyond said radially inner portion ( 54 ) of the piston ( 50 ) thereby providing said axial abutment to engage piston  50 .